This unusual device is essentially a canal lock. It’s used to move boats between the Forth and Clyde Canal and the Union Canal. Boats enter at the top or bottom, and then the whole thing rotates 180 degrees.

Tour boats operate on the canals and give visitors the chance to experience the wheel firsthand, but unfortunately it took us longer to get out of Edinburgh than we expected, and we arrived too late to take a ride. We did get to see one of the boats come along the Forth and Clyde Canal

and enter the lock that connects the canal with the basin at the bottom of the wheel:

Construction on the Forth and Clyde Canal began in 1768. The canal was closed in 1963 and reopened in 2001. The Falkirk Wheel began operation in 2002 and replaced a series of eleven locks that used to connect the two canals.